Strict validation of content length and chunk length. (#20)

Author: ioquatix

lib/protocol/http1/body/chunked.rb

@@ -35,12 +35,20 @@ def close(error = nil)
 					super
 				end
 
+				VALID_CHUNK_LENGTH = /\A[0-9a-fA-F]+\z/
+				
 				# Follows the procedure outlined in https://tools.ietf.org/html/rfc7230#section-4.1.3
 				def read
 					return nil if @finished
 
+					length, extensions = read_line.split(";", 2)
+					
+					unless length =~ VALID_CHUNK_LENGTH
+						raise BadRequest, "Invalid chunk length: #{length.dump}"
+					end
+					
 					# It is possible this line contains chunk extension, so we use `to_i` to only consider the initial integral part:
-					length = read_line.to_i(16)
+					length = Integer(length, 16)
 
 					if length == 0
 						@finished = true

lib/protocol/http1/connection.rb

@@ -398,10 +398,12 @@ def read_tunnel_body
 			HEAD = "HEAD"
 			CONNECT = "CONNECT"
 
+			VALID_CONTENT_LENGTH = /\A\d+\z/
+			
 			def extract_content_length(headers)
 				if content_length = headers.delete(CONTENT_LENGTH)
-					if length = Integer(content_length, exception: false) and length >= 0
-						yield length
+					if content_length =~ VALID_CONTENT_LENGTH
+						yield Integer(content_length, 10)
 					else
 						raise BadRequest, "Invalid content length: #{content_length}"
 					end

test/protocol/http1/connection.rb

@@ -208,15 +208,15 @@
 
 		with "HEAD" do
 			it "can read length of head response" do
-				body = client.read_response_body("HEAD", 200, {'content-length' => 3773})
+				body = client.read_response_body("HEAD", 200, {'content-length' => '3773'})
 
 				expect(body).to be_a ::Protocol::HTTP::Body::Head
 				expect(body.length).to be == 3773
 				expect(body.read).to be_nil
 			end
 
 			it "ignores zero length body" do
-				body = client.read_response_body("HEAD", 200, {'content-length' => 0})
+				body = client.read_response_body("HEAD", 200, {'content-length' => '0'})
 
 				expect(body).to be_nil
 			end

test/protocol/http1/connection/bad.rb

@@ -0,0 +1,125 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2019-2023, by Samuel Williams.
+
+require 'protocol/http1/connection'
+require 'connection_context'
+
+describe Protocol::HTTP1::Connection do
+	include_context ConnectionContext
+	
+	def before
+		super
+		
+		client.stream.write(input)
+		client.stream.close
+	end
+	
+	with "invalid hexadecimal content-length" do
+		def input
+			<<~HTTP.gsub("\n", "\r\n")
+			POST / HTTP/1.1
+			Host: a.com
+			Content-Length: 0x10
+			Connection: close
+			
+			0123456789abcdef
+			HTTP
+		end
+		
+		it "should fail to parse the request body" do
+			expect do
+				server.read_request
+			end.to raise_exception(Protocol::HTTP1::BadRequest)
+		end
+	end
+	
+	with "invalid +integer content-length" do
+		def input
+			<<~HTTP.gsub("\n", "\r\n")
+			POST / HTTP/1.1
+			Host: a.com
+			Content-Length: +16
+			Connection: close
+			
+			0123456789abcdef
+			HTTP
+		end
+		
+		it "should fail to parse the request body" do
+			expect do
+				server.read_request
+			end.to raise_exception(Protocol::HTTP1::BadRequest)
+		end
+	end
+	
+	with "invalid -integer content-length" do
+		def input
+			<<~HTTP.gsub("\n", "\r\n")
+			POST / HTTP/1.1
+			Host: a.com
+			Content-Length: -16
+			Connection: close
+			
+			0123456789abcdef
+			HTTP
+		end
+		
+		it "should fail to parse the request body" do
+			expect do
+				server.read_request
+			end.to raise_exception(Protocol::HTTP1::BadRequest)
+		end
+	end
+	
+	with "invalid hexidecimal chunk size" do
+		def input
+			<<~HTTP.gsub("\n", "\r\n")
+			POST / HTTP/1.1
+			Host: a.com
+			Transfer-Encoding: chunked
+			Connection: close
+			
+			0x10
+			0123456789abcdef
+			0
+			HTTP
+		end
+		
+		it "should fail to parse the request body" do
+			authority, method, target, version, headers, body = server.read_request
+			
+			expect(body).to be_a(Protocol::HTTP1::Body::Chunked)
+			
+			expect do
+				body.read
+			end.to raise_exception(Protocol::HTTP1::BadRequest)
+		end
+	end
+	
+	with "invalid +integer chunk size" do
+		def input
+			<<~HTTP.gsub("\n", "\r\n")
+			POST / HTTP/1.1
+			Host: a.com
+			Transfer-Encoding: chunked
+			Connection: close
+			
+			+10
+			0123456789abcdef
+			0
+			HTTP
+		end
+		
+		it "should fail to parse the request body" do
+			authority, method, target, version, headers, body = server.read_request
+			
+			expect(body).to be_a(Protocol::HTTP1::Body::Chunked)
+			
+			expect do
+				body.read
+			end.to raise_exception(Protocol::HTTP1::BadRequest)
+		end
+	end
+end